Security has been stepped up at Norwich Castle Museum after a number of items celebrating the life of the Norfolk naval hero Lord Nelson were taken.
The news comes at a time the museum's displaying an Italian masterpiece worth £100 million.
Police are reviewing CCTV and the National Security Adviser for the Arts Council is reviewing the museum's security arrangements.
The theft was noticed by an off-duty police officer who saw the cabinet which housed the objects had been tampered with.
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